Pension and Other Postretirement Benefits - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Pension Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 174	$ 316	$ 354	$ 632
Interest cost	1,317	1,094	2,677	2,184
Expected return on plan assets	(2,012)	(2,093)	(4,097)	(4,175)
Actuarial loss (gain) amortization	248	857	505	1,712
Prior service cost (income) amortization	2	3	5	5
Total net periodic benefit (income) cost	(271)	177	(556)	358
Postretirement Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	8	2	0	3
Interest cost	2	10	11	21
Expected return on plan assets	0	0	0	0
Actuarial loss (gain) amortization	(23)	0	(47)	0
Prior service cost (income) amortization	(9)	0	(8)	0
Total net periodic benefit (income) cost	$ (22)	$ 12	$ (44)	$ 24